1. Field of the Invention
The present invention relates generally to barriers for containing and controlling water-borne pollutants. More particularly, the invention relates to a water-borne pollutant containment boom of the type which is deployable from and retrievable on a reel.
2. Description of the Prior Art
As a result of the recent concern over pollution of the oceans, lakes and rivers with surface pollutants, particularly oil, there has been widespread development of floating containment booms for controlling the spread of pollutants, such as oil, on the surface of bodies of water and for assisting in removal of the pollutants from the water.
Generally floating booms designed to confine oil or other floating pollutants include an elongated panel adapted to be drawn around the area in which the oil or pollutant is to be confined which is buoyantly supported by floats or their equivalent. Preferably, these floating booms should be capable of being easily deployed and retrieved and compactly stored aboard vessels or aircraft.
Containment booms of the prior art have been of various designs, the common features of which include a wall-like barrier vertically supported in the water with a portion of the barrier extending above the surface of the water and a portion below the surface. Some of the prior art barriers have been relatively rigid and hinged in sections to permit folding in an accordion-like fashion for retrieval and storage while others have been of a flexible, continuous construction retrievable on reels. Because of the frequent deployment and retrieval and the movement from shore storage to shipboard or aircraft, booms are subjected to significant abrasion reducing the useful life of the boom.
Most booms are intended to be towed to some extent through the water in order to gather the pollutant in a confined area. This movement through the water imposes a longitudinal tension on the bottom edge of the boom under the surface of the water. With flexible booms, this water-imposed tension will distort or rupture the bottom edge of the boom absent a means for reinforcing the bottom edge. Tension-reinforcing means have included rigid clamp-like devices placed on the bottom edge of the boom or chains or metal cables attached along the length of the bottom edge. These prior art bottom edge-reinforcing devices have served the purpose of preventing rupture of the bottom edge of the boom and have contributed to the overall stability of the boom but have created difficulties with recovery and storage of the boom. The rigid structures, chains or metal cables preclude recovery of the boom on a reel as they abrade the surface of the boom on recovery. Removal of the structures, chains, etc., during recovery and reinstallation or deployment adds a significant, time-consuming step to the operation. Furthermore, the prior art reinforcing means have been bulky, snag or catch on protrusions aboard ship or aircraft, are difficult to clean after use with an oil spill or other pollutant, and are subject to corrosion.
Another difficulty in the prior art booms is the incorporation of the means for handling the booms in deployment, recovery and when it is desired to move the boom manually in the water for positioning or attachment to towing devices or other booms. Some prior art booms have included handles attached to the top of the boom to facilitate handling. These handles extend above the top of the boom adding additional dimension to the boom and creating additional problems in recovery and deployment of the boom, i.e., the handles catch or snag on protrusions in ships or aircraft and abrade the surface of the flexible boom that is retrieved on a reel.
The instant invention provides a flexible, water-buoyant boom designed to overcome the disadvantages of prior art booms. The boom of the invention incorporates a flexible tension member on the bottom edge of the boom which permits deployment from and retrieval on a reel without the disadvantages of the prior art tension members. Furthermore, the instant invention provides handles that are recessed into the top edge of the boom to provide a means for manually deploying, retrieving or moving the boom but overcomes the disadvantages of the prior art handles. In addition to removing the principal causes of abrasion, the boom of the instant invention is covered with a tough, oil- and abrasion-resistant coating that prolongs the useful life of the boom.